Innovative Wellbore Shielding Spacer Safely Pumped Across Narrow Area Accessories in Oilfield Cementing Operations

Abstract In oil and gas cementation, risks such as fluid loss to the formation may arise, necessitating the use of specialized fluids and materials of assorted sizes, types, shapes, and concentrations, which can increase the risk of restricting fluid flow within the well. This paper will cover the specifications of different surface and downhole restrictions where a specialized spacer paired with loss circulation material has been pumped successfully on narrow-area accessories. This study will focus on a wellbore shielding spacer, paired with an environmentally friendly loss circulation material (LCM) that has plugging capability up to 3,000 microns, used as a prevention and mitigation measure to control fluid loss during primary and remedial cementing operations, enhancing the mud removal, cement slurry coverage, bonding, zonal isolation, and overall well integrity. The spacer and the LCM have been tested in the lab for plugging efficiency and stability. Field applications of this fluid system will be discussed, including cementing applications that include the use of stage tools, float equipment, and liner hangers of different sizes. The wellbore shielding spacer and the environmentally friendly LCM have been used in multiple primary and remedial cementing operations, from large 13 3/8-in casing jobs down to 4 ½-in liners and downhole pressures above 10,000-psi and 300-F bottom hole temperature. At times, primary cementing operations require stage tools to perform cementing in multiple stages. This necessitates the spacer and cement to pass through narrow openings, which may be at risk of plugging. On deep cementing operations, liner cementation is applied to save cost and operational constraints on surface equipment during well construction; this type of operation will stress the cementing operations fluids to pass through narrow annular areas as the liner's tubular are mechanically hanged in the previously cemented casing. Check valves used in float equipment are used to withstand the differential hydrostatic pressure between the fluids in the annular space and inside the casing, while the cement slurry remains in the liquid state and transitions into solid. LCM can plug stage tools holes, liner hanger's narrow space, and float equipment valves, prematurely ending the cementing operations. The spacer system and LCM have been safely deployed, mitigating the fluid loss and enhancing the zonal isolation. This paper will include a compilation of different types and sizes of accessories where the wellbore shielding spacer has been deployed in conjunction with an environmentally friendly LCM, which will serve as a reference for similar operations. This system works best on applications where the equivalent circulating density is slightly above the formation fracture pressure.